1. Field of the Invention
The present invention relates generally to communication satellites, space stations, and the like which utilize solar panel arrays as a major source of power. More specifically, the invention relates to a multi-paneled solar array comprising a plurality of in-line panels pivotally connected for rotation between stowed and deployed positions and side panels pivotally connected to one or more of the in-line panels also for rotation between stowed and deployed positions, mechanisms being provided to prevent the side panels from deploying while the in-line panels are being deployed, and releasing them after the in-line panels are out of the way and fully deployed.
2. Description of the Prior Art
Collapsible and deployable structures in general are relatively well known and have been widely used in space applications to provide, for example, an antenna or the like for receiving and/or transmitting radio signals. Such collapsible structures advantageously can be stowed compactly in a space vehicle for launching into space and then deployed to the desired expanded configuration.
Generally, such devices are required to perform the following functions:
an actuating function, since the spacecraft is not always possessed of spinning motion; PA1 a damping function, to avoid the onset at the end of deployment of excessive stresses in the structure supporting the articulation device; PA1 a positioning function, called for by the very functions which the deployable structures are required to fulfill; and PA1 the function of equalizing the rates of opening of the different deployable structures, in order to prevent stability impairing asymmetrical forces from being engendered during rotation of the spacecraft. PA1 inertia forces due to a rotating motion that are superimposed upon the actuating function and call upon the damping function to operate over a very wide energy band; PA1 a wide temperature range; PA1 a high vacuum; and PA1 a weightless environment. PA1 high reliability; PA1 it provides deployment restraint for the side panels; PA1 it allows side-panel release after a specific in-line hingeline is latched; PA1 it requires no additional release pyros or remote commanding; PA1 it is simple, light weight, and inexpensive; and PA1 it fits within an existing launch vehicle envelope.
The execution of these functions is often closely linked to such strict requirements as: minimum size and weight; the exclusion of nonmetallic materials which may de-gas in space; the exclusion of magnetic materials; extreme accuracy in positioning the deployed appurtenances; and fail-safe operation.
Further, such systems must be capable of ensuring extension of the spacecraft elements under greatly varying conditions such as:
It is a principal objective of the present invention to provide a mechanism for satisfying the above-mentioned functions and the requirements for carrying out these functions.
The primary power source for communication satellites, space stations, and spacecraft in general are provided by solar arrays using some type of photovoltaic solar cells. The arrays are normally stowed against the satellite during launch, and deployed either after separation from the launch vehicle or once they are in their final orbital location. Deployment of a typical in-line rigid panel solar array (comprising a yoke and three to four panels) is synchronized using closed cable loops of a known construction. For higher power solar arrays, it is preferable to add secondary, or side, panels to the sides of the existing in-line panels, rather than to the end of the last in-line panel so as to keep the array structure to a reasonable length. Deployment and sequencing of these side panels must be coordinated with the deployment of the in-line panels such that they do not interfere with each other during deployment, and such that they are sequenced so that the side panels are released and deployed after completion of the in-line panel deployment. The mechanism required to initiate the release of these side panels is the subject of this invention.
Existing release mechanisms for such a side panel deployment may be comprised of a separate hold down and a release device actuated by a remote ground command Further, it is a requirement to release and deploy the side panels after completion of the in-line panel deployment.
Any separate hold down and release device for these side panels requires special hardware and software to activate and perform the release function. Use of any hardware or software introduces additional mass and complexity to the design.
An objective of this invention is to minimize the need for new hardware required to hold down the side panels from deploying while the in-line panels are being deployed, and release them after the in-line panels are out of the way and fully deployed.
A number of patents disclose various deployment hinge constructions which include a position locking device which is effected when a component such as a solar panel, antenna, reflector, or the like, is fully deployed. In this regard, U.S. Patents to Roth et al., U.S. Pat. Nos. 5,037,043 and 4,880,188 disclose spring biased solar panels having an actuating cam formed with a locking notch to prevent further movement once deployment is achieved. U.S. Pat. No. 4,290,168 to Binge discloses a damper for positively locked spring biased hinges. A variety of constructions of spring biased mechanisms for deploying solar panels and the like are disclosed in U.S. Pat. No. 4,780,726 to Archer et al. and U.S. Pat. No. 3,587,999 to Miniovitch et al.
Of more recent interest is the commonly assigned U.S. Pat. No. 5,673,459 to Baghdasarian which discloses deployment hinge apparatus comprising a stationary U-shaped bracket including a flange defining a retention recess. A hinge arm for supporting an operating structure such as a communication antenna reflector is pivotally mounted on the stationary bracket for movement between a stowed position and a deployed position. The hinge arm includes a deployment and latching cam which extends to a projecting nose member. A latch arm is pivotally mounted at one end to the stationary bracket and includes a cam follower at its other end operatively engageable with the cam. A spring biases the cam follower into engagement with the cam and is thereby effective to rotate the hinge arm from the stowed position to the deployed position such that, in the deployed position, the nose member and the cam follower are together snugly received in the retention recess, locking the hinge arm in the deployed position.
It was with knowledge of the foregoing state of the technology that the present invention has been conceived and is now reduced to practice.